Nectarine tree named ‘Burnectseven’

ABSTRACT

A new and distinct variety of nectarine tree ( Prunus persica ) var.  nucipersica , and which is denominated varietally as ‘Burnectseven’, and which produces an attractively colored yellow-fleshed clingstone nectarine which is mature for harvesting and shipment approximately July 15 to July 22 under ecological conditions prevailing in the San Joaquin Valley of Central California.

BACKGROUND OF THE NEW VARIETY

Botanical classification: Prunus persica.

Variety denomination ‘Burnectseven’.

The present invention relates to a new, novel and distinct variety ofnectarine tree, Prunus persica var. (nucipersica), which has beendenominated varietally as ‘Burnectseven’. The present variety ofnectarine tree resulted from an on-going program of fruit and nut treebreeding. The purpose of this program is to improve the commercialquality of deciduous fruit and nut varieties and rootstocks by creatingand releasing promising selections of prunus, malus and regia species.To this end we make both controlled and hybrid cross pollinations eachyear in order to produce seedling populations from which improvedprogenies are evaluated and selected.

The seedling ‘Burnectseven’ was originated by us from a population ofseedlings grown in our experimental orchards located near Fowler, Calif.The seedlings, grown on their own roots, were the result of a controlledcross of the nectarine tree ‘Summer Red’ (U.S. Plant Pat. No. 5,211)which was used as the seed parent and the nectarine tree ‘Diamond Ray’(U.S. Plant Pat. No. 8,948) which was used as the pollen parent. Oneseedling, which is the present variety, exhibited especially desirablecharacteristics and was marked for subsequent observation. After the1997 season, the new present variety was selected for advancedevaluation and repropagation.

ASEXUAL REPRODUCTION

Asexual reproduction of the new and distinct variety of nectarine treewas accomplished by budding to ‘Nemaguard’ Rootstock (non-patented).This was performed by us in our experimental orchard located nearFowler, Calif. Subsequent evaluations have shown those asexualreproductions run true to the original tree. All characteristics of theoriginal tree and its fruit were established and appear to betransmitted through succeeding asexual propagations.

SUMMARY OF THE VARIETY

‘Burnectseven’ is a new and distinct variety of nectarine tree, which isof large size, and which has vigorous growth, and is a regular andproductive bearer of large, firm yellow flesh, clingstone fruit withgood flavor and eating quality. The tree has a medium-high chillingrequirement of approximately 700 hours. The tree also producesrelatively uniformly sized fruit throughout the tree with a high degreeof red skin coloration, and firm flesh. The fruit appears to have goodhandling and shipping quality. Still further, the ‘Burnectseven’nectarine tree bears fruit that is ripe for commercial harvesting andshipment on approximately July 15 to July 22. In comparison to the seedparent ‘Summered’ Nectarine, (U.S. Plant Pat. No. 5,211) the new varietyripens 15 or more days earlier.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing which is provided is a color photograph of thepresent variety. It depicts a portion of the tree with two mature fruitprior to picking and characteristic twigs bearing typical leaves showingboth the dorsal and ventral coloration. The external coloration of thefruit is shown sufficiently matured for harvesting and shipment. Thecolors are as nearly true as is reasonably possible in a colorrepresentation of this type. Due to chemical development, processing andprinting, the leaves and fruit depicted in these photographs may or maynot be accurate when compared to the actual specimen. For this reason,future color references should be made to the color plates (RoyalHorticultural Society) and descriptions provided.

DETAILED DESCRIPTION

Referring more specifically to the pomological details of this new anddistinct variety of nectarine tree, the following has been observed inthe fourth fruiting season under the ecological conditions prevailing atorchards located near the town of Fowler, county of Fresno, state ofCalifornia. All major color code designations are by reference to TheR.H.S. Colour Chart (Fourth Edition) provided by The Royal HorticulturalSociety of Great Britain.

Tree:

Size.—Generally. — Considered medium large as compared to other commoncommercial nectarine cultivars ripening in the mid season of maturity.The tree of the present variety was pruned to a height of approximately314.8 cm to 386.7 cm at maturity.

Vigor.—Moderately vigorous. The present variety grew from about 141.0 cmto 195.7 cm in height during the first growing season. The variety waspruned to a height of approximately 106.7 cm in the first dormant seasonand primary scaffolds were selected for the desired tree structure.

Productivity.—Productive. Fruit set varies from 2.0 to several timesmore than the desired crop load. Fruit set is spaced by thinning todevelop into desired market sized fruit. The number of fruit set varieswith climatic conditions and cultural practices during the bloom periodand is therefore not distinctive of the variety.

Bearer.—Regular. Fruit set has been heavy and thinning was necessaryduring the past 4 years.

Form.—Upright, and pruned to a vase shape.

Density.—Medium dense. It has been discovered that pruning the branchesfrom the center of the tree to obtain a resulting vase shape allows forair movement and appropriate amounts of sunlight to enhance fruit colorand renewal of fruiting wood throughout the tree.

Hardiness.—The present tree was grown and evaluated in USDA HardinessZone 9. Winter chilling requirements are approximately 700 hours below7.0 degrees C. The variety appears to be hardy under typical Central SanJoaquin Valley climatic conditions.

Trunk:

Diameter.—Approximately 16.0 cm in diameter when measured at a distanceof approximately 15.24 cm above the soil level, at the end of the fourthgrowing season.

Bark texture.—Considered moderately rough, with numerous folds of paperyscarfskin being present.

Lenticels.—Numerous flat, oval lenticels are present. The lenticelsrange in size from approximately 2.0 to 5.0 millimeters in width, andfrom 1.0 to 2.0 millimeters in height.

Lenticel color.—Considered an Orange Brown, (RHS Greyed Orange N172 A).

Bark coloration.—Variable, but it is generally considered to be agrey-brown, (RHS Grey-Brown Group N199 B).

Branches:

Size.—Considered medium for the variety.

Diameter.—Average as compared to other varieties. The branches have adiameter of about 7.0 centimeters when measured during the fourth yearafter grafting.

Surface texture.—Average, and appearing furrowed on wood which isseveral years old.

Crotch angles.—Primary branches considered variable between about 45 to49 degrees from the horizontal axis. This characteristic is notconsidered distinctive of the variety however.

Current season shoots.—Surface texture — Substantially glabrous.

Internode length.—Approximately 2.3 to 2.4 cm.

Color of mature branches.—Medium brown, (RHS Grey Brown Group N199C).

Current seasons shoots.—Color — Light green, (RHS Yellow Green Group144D). The color of new shoot tips is considered a bright and shiny green(RHS Green Group 141 C).

Leaves:

Size.—Considered medium for the species. Leaf measurements have beentaken from vigorous, upright, current-season growth at approximatelymid-shoot.

Leaf length.—Approximately 150 to 175 millimeters.

Leaf width.—Approximately 35 to 40 millimeters.

Leaf base shape.—Slightly oblique relative to the leaf longitudinalaxis.

Leaf form.—Lancelolate.

Leaf tip form.—Acuminate.

Leaf color.—Dark green, (approximately RHS Green Group 137B).

Leaf texture.—Glabrous.

Lower surface.—Medium green, (RHS Green Group 138 B).

Leaf venation.—Pinnately veined.

Mid-vein.—Color. — Light yellow green, (RHS Yellow Green Group 145 C).

Leaf margins.—Slightly undulating. Form. — Considered crenate,occasionally doubly crenate. Uniformity. — Considered generally uniform.

Leaf petioles.—Size. — Considered medium long to long. Length. — 9.0 toabout 12.0 mm. Diameter. — 1.5 to about 2.5 mm. Color. — Pale green,(RHS Yellow Green Group 144 D).

Leaf glands.—Size. — About 1.0 mm in height and about 1.0 to 2.0 mm inwidth. Number. — Generally one per side, occasionally two or more perside. Type. — Reniform, considered reasonably unappressed to the petiolemargin. Color. — Greenish brown, (RHS Yellow Green Group146 B).

Leaf stipules.—Size. — Medium large for the variety. Number. — Typically2 per leaf bud and up to 6 per shoot tip. Form. — Lanceolate in form andhaving a serrated margin. Color. — Green, RHS Green Group 132 A) whenyoung but graduating to a yellow-brown color, (RHS Grey Orange group 177A) with advancing senescence. The stipules are considered to be earlydeciduous.

Flowers:

Flower buds.—Generally — The floral buds, depending on stage ofdevelopment are approximately 10 millimeters wide; and about 15millimeters long, conic in form; and slightly appressed relative to thebearing shoot.

Flower buds.—Color — The bud scales are reddish-brown, (approximatelyRHS Greyed Purple Group 183 A). The buds are considered hardy undertypical central San Joaquin Valley climatic conditions.

Hardiness.—No winter injury has been noted during the last several yearsof evaluation in The Central San Joaquin Valley. The current variety hasnot been intentionally subjected to drought or heat stress and thereforethis information is not available.

Date of first bloom.—Feb. 26, 2000.

Blooming time.—Considered mid-season in comparison to other commercialnectarine cultivars grown in the central San Joaquin Valley. Date offull bloom was observed on Mar. 2, 2000. The date of bloom variesslightly with climatic conditions and cultural practices.

Duration of bloom.—Approximately 8 days. This date varies slightly withclimatic conditions.

Flowers type.—The variety is considered to have a showy type flower.

Flower size.—Flower diameter at full bloom is approximately 40.0 to 44.0millimeters.

Bloom quantity.—Considered abundant.

Flower bud frequency.—Normally 1 to 2 appear per node.

Petal size.—Generally — Considered large to very large for the species.Length. — Approximately 18.0 to 20.0 millimeters. Width. — Approximately17.0 to 19.0 millimeters.

Petal form.—Broadly ovate.

Petal count.—Nearly always 5.

Petal texture.—Glabrous.

Petal color.—Light pink when young, (RHS Red Purple Group 62 B), anddarkening with advancing senescence and exposure to sunlight to a mediumto dark pink, (RHS Red Purple Group 62 A).

Fragrance.—Slight.

Petal claw.—Form. — The claw is considered truncate and has amedium-large size when compared to other varieties. Length. —Approximately 8.0 to 10.0 millimeters. Width. — Approximately 7.0 to 9.0millimeters.

Petal margins.—Generally considered variable, from nearly smooth, tomoderately undulate and ruffled, especially apically.

Petal apex.—Generally — The petal apices appear somewhat elongated andslightly domed.

Flower pedicel.—Length. — Considered medium-long, and having an averagelength of approximately 3.0 to 4.0 millimeters. Diameter. — Consideredaverage, approximately 2.0 millimeters. Color. — A medium brown, (RHSGrey Brown Group N199 D).

Floral nectaries.—Color. — A Dull orange-gold, (RHS Greyed Orange Group169 B).

Calyx.—Surface texture. — Generally glabrous. Color. — A dull red,(approximately RHS Greyed Purple Group 183 A).

Sepals.—Surface texture. — The surface has a short, fine, and woolytexture. Size. — Average, and ovate in form. Color. — A dull red,(approximately RHS Greyed-Red Group 178 A).

Anthers.—Generally. — Average to above average in length. Color. — Redto reddish-orange dorsally, (approximately RHS Greyed Red Group 179 A).

Pollen production.—Pollen is abundant, and has a yellow color,(approximately RHS Yellow Orange Group 17 B).

Filaments.—Size. — Variable in length, approximately 11.0 to 13.0millimeters in length. Color. — Pinkish-white, (RHS Red Purple Group 62D).

Pistil.—Number. — Usually 1, rarely 2. Generally. — Average in size.Length. — Approximately 15.0 to 18.0 millimeters including the ovary.Color. — Considered a very pale green, (approximately RHS Yellow GreenGroup 151 D). Surface Texture. — The variety has a long glabrous pistil.

Fruit:

Maturity when described.—Firm ripe condition (shipping ripe). Date offirst picking. — Jul. 15, 2000. Date of last picking. — Jul. 22, 2000.The date of harvest varies slightly with climatic conditions.

Size.—Generally — Considered large, and uniform.

Average cheek diameter.—Approximately 76.0 to 78.0 millimeters.

Average axial diameter.—Approximately 74.0 to 76.0 millimeters.

Typical weight.—Approximately 251.0 grams. This is highly dependent uponcultural practices and therefore not distinctive of the variety.

Fruit form.—Generally — Moderately oblate. The fruit is generallyuniform in symmetry.

Fruit suture.—Shallow, occasionally lipped, and extending from the baseto apex. No apparent callusing or stitching exists along the sutureline.

Suture.—Color — This appears to be a yellow to golden yellow background,(approximately RHS Orange Group 26 B) and occasionally having some redcoloration, (approximately RHS Red Group 46 B).

Ventral surface.—Form — Slightly indented.

Apex.—Rounded.

Base.—Retuse.

Stem cavity.—Rounded to slightly elongated in the suture plane. Averagedepth of the stem cavity is about 1.45 cm. Average width is about 2.41cm.

Fruit skin.—Thickness. — Considered medium in thickness, and tenaciousto the flesh. Texture. — Glabrous. Taste. — Non-astringent. Tendency tocrack. — None observed.

Color.—Blush color. — This red blush color is variable from a reddishorange, (approximately RHS Red Orange Group 34 A) to a dark red,(approximately RHS Red Group 45 C). The blush color ranges from about70% to about 90% of the fruit surface depending on sunlight exposure andgrowing conditions. Ground Color. — Yellow orange, (approximately RHSYellow Orange Group 21 B).

Fruit stem.—Medium in length, approximately 7.0 to 8.0 millimeters.Diameter. — Approximately 2.0 to 3.0 millimeters. Color. — Paleyellow-green, (approximately RHS Yellow Green Group 144 D).

Flesh.—Ripens. — Evenly. Texture. — Firm, and dense. Fibers. — Few,small, and tender. Aroma. — Very slight. Eating Quality. — Very good.Flavor. — Considered sweet and mildly acidic. The flavor is consideredboth pleasant and balanced. Juice. — Moderate. Brix. — About 13.0degrees. This characteristic varies slightly with the number of fruitone the tree, prevailing cultural practices and surrounding climaticconditions. Flesh Color. — Pale yellow, (approximately RHS Yellow OrangeGroup 16B).

Stone:

Type.—Clingstone.

Size.—Considered medium for the variety.

Length.—Average, about 23.0 to about 25.0 millimeters.

Width.—Average, about 22.0 to about 23.0 millimeters.

Diameter.—Average, about 19.0 to 20.0 millimeters.

Form.—Obovoid.

Base.—The stone is usually rounded, but it may vary from rounded tostraight.

Apex.—Shape. — The stone apex is raised and has an acute, short tip.

Stone surface.—Surface Texture — Irregularly furrowed toward the apex,and pitted toward the base. The stone exhibits substantial pittinglaterally. Substantial grooving over the apical shoulders is evident.Surface pitting is prominent generally, and more frequently, it ispresent basally. Ridges. — The surface texture varies from sharp torounded. Ventral Edge. — Width — Considered medium, and having adimension of approximately 3 to 4 millimeters at the mid-suture. Thewings are most prominent over the basal area. Dorsal Edge. — Shape. —Full, heavily grooved, and having jagged edges. The dorsal edge ismoderately eroded over the apical shoulder.

Stone color.—The color of the dry stone is a dull red, (approximatelyRHS Greyed Red Group 179B).

Tendency to split.—Very infrequent splitting was noted.

Kernel.—Size. — Length 17.0 mm. Width — 14.0 mm. Thickness — 3.0millimeters. Form. — Obovoid. Pellicle. — Pubescent. Color. — (RHSGreyed Orange Group 166 C).

Use.—The subject variety ‘Burnectseven’ is considered to be a Nectarinetree of the late mid-season maturity, and which produces fruit which areconsidered very firm, attractively colored, and which are useful forboth local and long distance shipping.

Keeping quality.—Excellent. Fruit has stored well up to 21 days afterharvest at 1.0 degree Celsius.

Shipping quality.—Good. Fruit showed minimal bruising of flesh or skindamage after being subjected to normal harvesting and packingprocedures.

Resistance to insects and disease.—No particular susceptibilities werenoted. The present variety has not been tested to detect for anysusceptibilities or resistances to any known plant and/or fruitdiseases.

Although the new variety of nectarine tree possesses the describedcharacteristics when grown under the ecological conditions prevailingnear Fowler, Calif., in the Central part of the San Joaquin Valley ofCalifornia, it should be understood that variations of the usualmagnitude and characteristics incident to changes in growing conditions,fertilization, pruning, pest control and horticultural management are tobe expected.

Having thus described and illustrated our new variety nectarine tree,what we claim is new and desire to secure by Plant Letters Patent is: 1.A new distinct variety of nectarine tree substantially as illustratedand described, and which is characterized principally as to novelty byproducting an attractively colored yellow-fleshed clingstone nectarinewhich is mature for harvesting and shipment approximately July 15 toJuly 22 under the ecological conditions prevailing in the San JoaquinValley of Central California.